Synthesis of orthogonally protected 3,8-diazabicyclo[3.2.1]octane-2-carboxylic acid--a versatile building block for the synthesis of cocaine analogues

An eight-step synthesis of an orthogonally protected 3,8-diazabicyclo[3.2.1]octane from commercially available pyroglutamic acid was developed. The target compound can be used as a versatile building block for combinatorial synthesis of pharmacologically useful compounds and features a hidden α-, β-, δ- and ε-amino acid, which can also be seen as an example of a new class of cocaine analogues.